Process for the treatment of waste liquors from soda pulp processes, &amp;c.



UNITED STATES PATENT OFFICE.

vxoco DREWSEN, or BROOKLYN, NEW YORK. ASBIGNOR T0 wus'r vmonua run aPAPER oomramr, or new roux, n. 2., A conrona'rxou or nunawm.

PROCESS FOR THE TREATMENT OF WASTE LIQUOBS FROM SODA PULP PROCESSES, &o.

Ho Drawing.

To all whom. it may concern:

Be it known that I, Vrooo Dunwsnn, a citizen of the United States andresident of the boron h of Brooklyn, county of Kings, city and gtate ofNew York, have made a certain new and useful Invention Relating toProcesses for the Treatment of Waste Li uors from Soda Pulp Processes,&c., of which the following is a specification.

This application is a continuation in part of my co-pending applicationSerial No. 811,676, filed January 12, 19,14, and contains subject-mattertaken therefrom.

This invention relates especially to the treatment of soda waste liquor,known as black li nor, and which is formed when paper pu p ismanufactured from deciduous or other woods by the caustic soda process,this black liquor being preferably first concentrated as by evaporationuntil it contains only about fifty per cent. or so of water. Additional.caustic alkali such as caustic soda may also be advantageouslyincorporated with the concentrated waste li nor in some cases before thematerial is siilijected to dry distillation, and if desired, suchadditional caustic soda to the extent of about fifteen to thirty percent. or so of the weight of the organic matter present may beincorporated with the concentrated waste liquor; the mixture beingpreferably heated and boiled, at a temperature of about 125 centigradefor an hour 0? more, until more of the water is boiled oil and thedesired. incorporation and conversion action takes place. Theconcentrated soda waste liquor. with or Without the incorporation ofsuch additional caustic alkali therewith, maybe causticized bythoroughly incorporating therewith powdered quic lime to the extent ofthirty-five to sixty per cent. or so of the weight of the concentratedwaste soda liquor, withwhich it combinesin connection with the slakingof the quicklinle by the water present, part of which is thereby drivenoil. Causticized calcareous ligne- 011s acetate material may thus beformed which is in permanently solid condition so as not to undesirablymelt or foam under dry distilling conditions, and it may be in the formof a substantially dry powder or granulated material when about fiftyper Specification of Letters intent.

Application fllcd July 23, 1918. Scrtal No. 848,880.

'Patented Mar. 25, 1919.

cent. of powdered zl uicklime is used. The causticized motcria may besubjected to distillation at hi h temperatures preferably withsuperheated steam and during the distillation is preferably graduallyand uniformly heated while being agitated, which results in the recovero largeproportions of acetone, methyl 2. cohol and other valuablematerials.

By this process large uantities of acetone evaporators untilconsiderably concentrated as when the concentration is carried forenough to reduce the profportion of Water in the material to about fi typer cent. or so. The usual, black liquors preferably when concentratedto such thick syrupy consistency may be subjected to a supplementalconverting process with additional caustic alkali, such as caustic sodato the extent of about fifteen to thirty per cent. of the weight of theorganic matter present in the concentrated solution, twenty per cent. ofcaustic soda giving goods results. the mixture to secure thoroughincorporation being preferably heated or boiled under suitable pressureor even in some cases under a partial vacuum for a considerable time,the

treatment extending about an hour or two in a digester or openevaporator in which the mixture is boiled at a temperature of about 120to 140 degrees centigrade, but preferably at about 125 degreescentigrade. This heat conversion treatment may also affect eliminationof still further proportions of water, when as is desirable the steam isallowed to escape.

The concentrated soda waste liquor with or without the incorporation ofsuch additioual caustic alkali therewith may advantageously hecausticized by the incorporation of powdered quicklimc to the extent ofthirty-fivc to sixty per cent. or so of the. weight of the concentratedsoda waste liquor which may contain about. fifty per cent. of water. Onthoroughly iimorporatint, therewith fifty per cent. for instance ofpowdered quicklime, which is considerably more than the amount. oforganic material present, the quicklimc is slalced and seems to combinewith the. organic material. considerable water being driven oil' by theheat of slaking. The causticizcd material which may thus be formed,containing considerable acetate compounds, is permanently solid underdry distilling conditions so as not to undesirably melt. or foam in thestill and thus give. trouble and prevent the uniform heating which isdesirable in this connection. It is not. of course, necessary in allcases to incorporate as much as fifty per cent. of powdered quicklimc'with concentrated soda waste liquor containing about fifty per cent. ofwater. since the incorporation of thirty five or forty per cent. or soof quicldime therewith lives a causticizcd material which can be largelyor completely dehydrated in various ways and then remains permanentlysolid under destructive distillation. Furthermore, in some cases wherethe concentrated soda waste liquor originally contains less water thepercentage of incorporated quicklime may be correspondingly stillfurther reduced to some extent. although it is desirable to use.preferably substantially uniformly incorporated throughout the mass. notonly ample qnicklimc or other alkali material to combine with the.organic material before and during destructive distillation. but also tobe capable of rendering the causticized material permanently solid underdistilling conditions. The combined soda in this causticized calcareousligneous acetate material may be. largely or practically completelyconverted into the caustic soda form where fifty per cent. or so ofquicklimc is used and this has the additional advantage that whenthc"earbonized distillation residue is leached the dissolved soda issubstantially in the caustic condition desirable for woodpulp'cohkingliquors so that further caustitiizntg is unnecessary. Where fifty percent. or so of powdered quicklime is used the continued agitation orstirring of the mixture may eliminate sufficient water so that thecausticized material is in finely granulated or substantially drypowdered form. V

The granular or finely divided caustieized material thus obtained maythen be distilled in any suitable retort with superheated .steam. forexample. at 300 to '500 degrees centigrade or so and large quantities ofacetone or methyl alcohol are thus secured, togather with considerableadditional amounts of black oily material. It is in some cases desirablethat precautions be taken to minimize or prevent; destructive or otherundesirable oxidizing action on such calcareous ligncous acetatematerial prior to and dur ing the distilling thereof, and therefore tominimize its contact with air or other oxidizing medium, especially whenthe acetate material is substantially dry and hot. It is thus desirable.where the causticized ligneous acetate. material contains no more than afew per cent. or so of moisture, to distil the same promptly after it isformed, or to store it in a neutral or substantially non-oxidizingatmosphere or at least out of undesirable contact; with oxygen or otheroxidizing material which might materially decrease the yield of acetoneand the like. When treating black liquor produced when poplar wood isdigested inthe usual soda process of making wood pulp, yields of acetoneand methyl alcohol have been secured as high as five to ten per cent. ormore of the wcight'of the organic matter in the waste liquor, togetherwith small quanti ies of allied volatile solvents, such as the hignerketone solvents. etc. There may also be secured in this distillationsome three to ten per cent. of heavier oily solvent bodies which as awhole are lighter than water and which contain considerable waterimmiscible material. There is. of course. a large proportion of othermore volatile material of a gaseous nature given off during thedistillation and which is sutlicicntly inflammahlc so as to be used forretort heating and other heating purposes. if desired.

The products of the distillation of the converted causticized ligneonsacetate material may be separated or fractionated in any suitable way soas to separate the more valuable volatile solvent materials from theother materials as by repeated distillation in a. column still, forexample. or in other ways. The distillation residue in the retort may.of course, be submitted to still higher heatand may be finally burned inthe presence of air and the caustic or other valuable mineral matter maybe separated as by leaching with hot water. for example. which dissolvesthe soda' present and permitsit to be recovered largely in the form ofcaustic soda with some little carbonate of soda while. the remaininginsoluble material may. if de' sired. be burned in a suitable kiln torecover the lime.

This invention has been described in connection with a number ofillustrative apparatus, materials. proportions arrangementstemperatures. pressures, times and orders'of steps. to the details ofwhich disclosure the invention is not of course to be limited since whatis claimed as new and what is desired to be secured by Letters Patent isset forth in the appended claims:

The process of treating the Waste liquor produced the manufacture ofwood pulp from deciduous woods by the soda pulp process, which consistsin concentrating the waste liquor by evaporation until the proportion ofwater in the concentrated material is only about fifty per cent. inincorporating with the concentrated waste liquor caustic soda to theexteritjof about twenty per cent. of the organic matter present andboiling the relic ture under pressure at about 125 degrees centigradeforat least an hour until conversion takes place and the mixture is furtherconcentrated by evaporation, in reducing the convertedconcentratedmaterial to u suhstum tially dry powdered cuusticized material byincorporeting therewith powdered quicklime to uii amount at least aboutequal in weight to the organic matter present, in subjecting thesubstantially dry ceusticizeii ineteriul to distillation withsuperheetcsil steam at about 300 to 500 degrees centigrnrie to recoveracetone, methyl alcohol and additional allied volatile solvent materialto the extent. of five to ten per cent. or more of the organic matter inthe original waste liquor.

2. The process of treating the waste liquor produced in the manufactureof wood pulp y the soda pul process, which consists in conccntrntin t 1ewaste liquor, in incorporating wit: the concentrated waste liquorcaustic souu to the extent of about twenty per cent. of the organicmatter present and boiling the mixture, in reducing such concentratedmaterial to a substantially. dry causticizcd material by incorporatingthere with quicklime to an amount at least about equal in weight to theorganic matter pres ent, in subjecting the substantially dry causticizedmutcrinl to distillation with steam to recover acetone and additionalallied Haiti'- tile solvent material and additional heavier oil solventhodies.

The process of treating the waste liquor produced in the manufacture ofwood pulp by the soda pulp process, which consists in concentrating thewaste liquor, in incorporating with the concentrated waste liquorcaustic-soda, in reducing the converted concentrated material to Ipernmnently solid cuusticized material by intimately incorporatinquicklime therewith, and in suhg'ccting tie ceusticized material to drydistilletion to recovcr volatile solvent nuiteriel.

4. The process of treating the waste liquor.

produced in the manufacture of wood pulp by the oda pulp process. whichconsists in concentrating the waste liquor by Ofzifltilzllion until theproportion of water in the con ccntratcd material is only about fiftyper cent, in incorporating additional caustic alhall therewith andboiling the mixture, in. incorporating with the concentrated materialquichliine to an mnount at least about equal in weight to the organicmaterial pres cut to convert it into n substantially dry ceusticizcdacetate nutGcrial which is permw nentlv solid under dry distillingconditions, and in slowly and uniformly heatin and illStilliil thesubstantially ry causticized meterie with superheated steam at about 300to 500 degrees centigrade to recover acetone, methyl alcohol and alliedvolatile so1- vent material to the extent of five to ten per ,cent. ormore of the organic material present in the waste liquor.

5. The process of treating the waste liquor reduced in the manufactureof wood pulp y the causticsoda process. which consists in incorporatinwith the cmicentrated waste liquor caustic alkali to the extent of atleast about fifteen 1' cent. of the organic matter present and oilingthe mixture, in incorporeting with the converted concentrated materielslltuli inuicriul to convert ii. into n ceusticizeol material which ispermanently solid so as not to ohiectionuhly melt or foam under drydistilling conditions and in su h jccting the cuusticizcd material todry tlir+ tilletion with superheated steam to recover five to ten percent. or more of acetone end additional allied volatile solventmaterial.

8. The process of treating waste liquor reduced In the nmnufncture ofwood pulp liy'the soda pulp process, which consists in concentrating thewaste liquor by evepiarw ion until the proportion of water in theri'z-ncentratcd material is below fifty per cent. and incorporetintherewith caustic alkali to the extent of at cost shout twenty per cent.of the organic matter present, in reducing the converted concentratedmaterial to a substantially dry cnusticized ci'mdition by incorporatingthcrmvith quicklime to on amount itt least. about equal in weight. tothe organic mutter present. and in suhiecting the suhstnntiully drycuusticized material to distillation to recover live to ten per cent. ormore of acetone. methyl alcohol and ndditional allied volatile solventmaterial and additionel heavier oil solvent bodies.

i. The process of treating the waste liquor produced in the manufactureof wood pulp hy the s (in pulp process, which consistent boiling t esome. in incorporating; therewith ulknli material to convert it into nczrustr cized material which is permanently solid so its not toohjectionuhly melt or foam under dry distilling conditions, and insubjecting the cuusticized muterielfto drydistillution to recover fiveto .ten per cent. or more of itcetone and additional allied volatilesolvent material.

8. The process of treating the waste liquor produced in the manufactureof wood pulp hy the soda pulp p1*:. cc:- nhich consists in icmircntrating the waste liquor by evaporation and incorporatingadditional caustic alkali therewith, in thoroughly incorporating withthe coin-entrated material quieklime to convert it into a causticizedacetate n1aterial which is permanently solid under dry distillingconditions. and in slowly and unit'oriuly heating and dis-tilting thecausticizcd material with steam at al out i tltl to 500 do grecs.ccntigrade to recover live to ten per cent. or more of aeetonm methyl.alcohol and additional allied volatile solvent material.

it. The process of treating the waste liquor produced in the manufactureof wood pulp by the soda pulp recess, which eonsists in concentmliun litwaste liquor by cvapr tiring and in incorporating with the concentratedmaterial quieklime to Convert. it into a eausticizedacetate materialwhich is prrinaiwntly solid under dry distillation conditions, and indistilling the eaustieized material to recm'cr acetone. metihyl-aleoholand additional allied volatile solvent material.

l 'lhe process of treating; the waste Soda liquor produced by thecaustic soda pulp process. which consists in concentrating the wasteliquor hy evaporation until the proportion of water in the eolu-entratedmaterial is only about fifty per cent. in redueing the concentratedmaterial to substantially dry causticizzml material by thorougrlyincorporating tlicrewith quieklinie to an amount between about illlli?\'-fi\'l and sixty per cent. by Weight of said concentrattal 1nateriahand in snlijeeting the substantially dry raustieixed material todistillation with strain at about 306 to 500 degrees centrigrade torecover five to ten per cent. or more of acetone and additional alliedvolatile solvent material.

11. The process of treating the waste soda liquor produced by thecaustic soda pulp process. which consists in concentrating the Wasteliquor by evaporation until the pr0- hortion of water in thecom-entrated material is no more than about fifty per cent. in reducingthe concentrated material to substantially dry caustieized material byincorporating therewith qnielilimc to an amount over thirty five percent. hv weight of said concentrated material. and in subjecting thesubstantially dry caustieizeil Inatci'ial to dry di. illation andminimizing undesirable oxidizing action on said caustieized materialuntil it is distilled to recover five to ten per cent. or more ofacetone and additional allied volatile solvent material.

1'). The process of treating; the Waste liquor produced in the treatmentof fibrous vegeta le material by the soda process, which consists inoncentrating the waste liquor and incorporating therewith considerahleadditional eaustie soda, in reducing the concentrated material to acaustieized material which is substantially permanently solid under drydistilling conditions by incorporating therewith powdered quieklime tothe extent of more than sixty per cent. by weight of the solids in saidconcentrated material and in gradually heating and dry distilling theeaustieizcd material to recover therefrom acetone and additional alliedvolatile solvent material.

13. The process of treating the waste liquor produced in the treatmentof fibrous vegetable material by the caustic soda process which consistsin eonet'aitrating the waste liquor, in reducing the concentratedmaterial to a eausticized material which is substantially permanentlysolid under dry distilling conditions by incorporating therewithqnicklixne to the extent. of more than fifty per cent. by weight of thesolids in said concentrated material and in grzuiually heating and drydistilling the caustieized material and minimizing undesirable oxidizingaction on said eausticized material until it is distilled to recovertherefrom acetone and additional allied volatile solvent ina tcrial.

H. The process of treating the waste liquor produced in the treatment offibrous vegetable material hy the eanstie alkali process which consistsin ranaeent-rating the waste liquor. in ri ducing the concentratedmaterial to a eaustieized material which is substantiall v permanentlysolid under dry dist illinn' c-oaslitious h v iucorporatino th withqniclclime and in dry distilling the oa'usticizcd material to recovertherefrom acetone and additional allied volatile solvent material.

"ihe process of treating the waste liquor produced in he manufacture ofwood pulp by the caustic soda pulp proecss. which consists inconcentrating the Waste liquor, in reducing the concentrated material toa eubstantially dry causticizcd ligneous aeetatc material by thoroughlyincorporating powdered quickliine thermvitli, in substantiallypreventing undesirable oxidizing action on said eausticized lig'neousacetate material until it is distilled. and in out jectiiu: thesubstantially dry zausticized material to distillation to recoveracetone and additional allied volatie material.

Ill. The process of treating the waste liquor produced in themanufacture of wood pulp by the soda. pulp process. which eonsists inconcentrating the Waste liquor, in reducing the concentrated material toa austiciaed ligneous acetate material by incorporating qniclcliinctherewith. in minimizing undesirable oxidizin; action on saidcausticizcd linueons acetate material until it is distilled. and insubjecting the cansticized material t0 distillation to recover with totransform the resulting mixture into acetone and additional alliedvolatile masubstantially dry condition and produce 10 tei-iul.rruusticizeil ligneous acetate material, and in 17. The process oftiwiatiug, the waste subjecting the substantially dry causticized 5liquor prmlucm] in T llv manufacture of woocl ll'liltll'llll tndistillation to recover acetone pulp by this mm pulp process, which6011- and mlilit'imml allied volatile. mateiial. sists in wiusvulmtingthe Waste liquor, in

incm'pm'ating powdered quickliine there- VIGGO DREWSEN.

